Misconfiguration causing many errors in the hook logs

[wallrj]

$ kubectl logs deploy/hook | jq | fgrep  -C 10 error
...
{
  "component": "hook",
  "error": "Post \"http://needs-rebase\": dial tcp 10.31.251.8:80: connect: connection refused",
  "event-GUID": "6b8398f0-88d9-11ec-9083-d6a9f0825356",
  "event-type": "pull_request",
  "external-plugin": "needs-rebase",
  "file": "prow/hook/server.go:225",
  "func": "k8s.io/test-infra/prow/hook.(*Server).demuxExternal.func1",
  "level": "error",
  "msg": "Error dispatching event to external plugin.",
  "severity": "error",
  "time": "2022-02-08T12:20:27Z"
}
{
  "component": "hook",
  "error": "Post \"http://cherrypick\": dial tcp 10.31.255.164:80: connect: connection refused",
  "event-GUID": "6b8398f0-88d9-11ec-9083-d6a9f0825356",
  "event-type": "pull_request",
  "external-plugin": "cherrypick",
  "file": "prow/hook/server.go:225",
  "func": "k8s.io/test-infra/prow/hook.(*Server).demuxExternal.func1",
  "level": "error",
  "msg": "Error dispatching event to external plugin.",
  "severity": "error",
  "time": "2022-02-08T12:20:33Z"
}